Untar the correct venv as a part of preparing the xdist worker.

scripts/xdist/prepare_xdist_nodes.sh

@@ -23,6 +23,8 @@ do
     worker_reqs_cmd="ssh -o StrictHostKeyChecking=no jenkins@$ip
     'git clone --branch master --depth 1 -q https://github.com/edx/edx-platform.git; cd edx-platform;
     git fetch -fq origin ${XDIST_GIT_REFSPEC}; git checkout -q ${XDIST_GIT_BRANCH};
+    rm -rf $HOME/edx-venv;
+    tar -C $HOME -xf $HOME/edx-venv_clean-$PYTHON_VERSION.tar.gz;
     source ../edx-venv/bin/activate;
     pip install -q ${DJANGO_REQUIREMENT} -r requirements/edx/testing.txt; mkdir reports' & "